Abstract
Objective: To describe the main characteristics of chronic atrial fibrillation and to present catheter ablation as an effective therapeutic alternative. Detail of the case: This is a case report of a patient with enlarged left atrium and chronic AF with difficult to control, who after undergoing optimized drug treatment and subsequent unsuccessful electrical cardioversion, obtained an efficient response with catheter ablation of intracardiac electrophysiological study (EPS) and consequent resolution of AF. EPS is a form of cardiac catheterization, whereby the circuit responsible for tachycardia can be identified and the focus blocked by means of a discrete thermal injury caused by the catheter itself already inserted, providing the elimination of the stimulating of the arrhythmia. Final considerations: The work exposes this new therapeutic alternative, as well as its advantages in relation to conventional treatments already established and the possibility of a greater benefit in the prognosis of patients with AF that are difficult to control.